fix(hosts): delete five dead HostConfig fields

metadataFormat (generator hardcodes openai.yaml), sidecar (behavior lives in
setup's create_agents_sidecar — knowledge preserved as a comment in codex.ts),
install.prefixable (skill_prefix is implemented entirely in bin/gstack-config),
staticFiles (docstring cited a SOUL.md that never existed anywhere), and
adapter (its only would-be consumer, openclaw-adapter.ts, was fully dead —
with a test asserting the field was undefined). Kept: learningsMode (wired
next), linkingStrategy (validation reads it), coAuthorTrailer (consumed by
resolvers/utility.ts).

Proof: JSON dump diff shows ONLY the deleted keys vanishing; zero-diff regen
across all 10 hosts; host-config + gen-skill-docs suites green. Note: this
commit also carries chunk-23 edits to the shared hosts/claude.ts +
define-host.ts + host-config.test.ts files (skipSkills collapse, stale
line-number comment drops) — pathspec commits, concurrent prep.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/host-config.ts

@@ -56,10 +56,8 @@ export interface HostConfig {
 
   // --- Generation ---
   generation: {
-    /** Whether to create sidecar metadata file (e.g., openai.yaml for Codex). */
+    /** Whether to create a metadata file alongside skills (always openai.yaml; gen-skill-docs hardcodes the format). */
     generateMetadata: boolean;
-    /** Metadata file format (e.g., 'openai.yaml'). */
-    metadataFormat?: string | null;
     /** Skill directories to exclude from generation for this host. */
     skipSkills?: string[];
     /** Skill directories to include (allowlist). Union logic: include minus skip. */
@@ -81,18 +79,8 @@ export interface HostConfig {
     /** Dir → explicit file list for selective file linking. */
     globalFiles?: Record<string, string[]>;
   };
-  /** Optional repo-local sidecar config (e.g., Codex uses .agents/skills/gstack). */
-  sidecar?: {
-    /** Sidecar path relative to repo root (e.g., '.agents/skills/gstack'). */
-    path: string;
-    /** Assets to symlink into sidecar (different set than global). */
-    symlinks: string[];
-  };
-
   // --- Install Behavior ---
   install: {
-    /** Whether gstack-config skill_prefix applies (Claude only). */
-    prefixable: boolean;
     /** How skills are linked into the host dir. */
     linkingStrategy: 'real-dir-symlink' | 'symlink-generated';
   };
@@ -104,11 +92,6 @@ export interface HostConfig {
   learningsMode?: 'full' | 'basic';
   /** Anti-prompt-injection boundary instruction for cross-model invocations. */
   boundaryInstruction?: string;
-
-  /** Static files to copy alongside generated skills (e.g., { 'SOUL.md': 'openclaw/SOUL.md' }). */
-  staticFiles?: Record<string, string>;
-  /** Optional path to host-adapter module for complex transformations. */
-  adapter?: string;
 }
 
 // --- Validation ---